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* vm pager: writemapping accounting for OBJT_SWAPKyle Evans2019-09-031-4/+0
| | | | | | | | | | | | | | | | | | | | | Currently writemapping accounting is only done for vnode_pager which does some accounting on the underlying vnode. Extend this to allow accounting to be possible for any of the pager types. New pageops are added to update/release writecount that need to be implemented for any pager wishing to do said accounting, and we implement these methods now for both vnode_pager (unchanged) and swap_pager. The primary motivation for this is to allow other systems with OBJT_SWAP objects to check if their objects have any write mappings and reject operations with EBUSY if so. posixshm will be the first to do so in order to reject adding write seals to the shmfd if any writable mappings exist. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D21456 Notes: svn path=/head/; revision=351795
* sys: further adoption of SPDX licensing ID tags.Pedro F. Giffuni2017-11-201-0/+2
| | | | | | | | | | | | | | | | | Mainly focus on files that use BSD 3-Clause license. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. Special thanks to Wind River for providing access to "The Duke of Highlander" tool: an older (2014) run over FreeBSD tree was useful as a starting point. Notes: svn path=/head/; revision=326023
* Mark pages after EOF as clean after pageout.Konstantin Belousov2017-07-261-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Suppose that a file on NFS has partially filled last page, and this page is dirty. NFS VOP_PAGEOUT() method only marks the the page clean up to the block of the last written byte, leaving other blocks dirty. Also any page which erronously exists in the vnode vm_object past EOF is also left marked as dirty. With the introduction of the buf-cache coherent pager, each pass of syncer over the object with such page results in creation of B_DELWRI buffer due to VOP_WRITE() call. This buffer is noted on next syncer pass, which results e.g. a visible manifestation of shutdown never finishing vnode sync. Note that before buf-cache coherency commit, a dirty page might left never synced to server if a partial writes occur. Fix this by clearing dirty bits after EOF. Only blocks of the partial page which are completely after EOF are marked clean, to avoid possible user data loss. Reported by: mav Reviewed by: alc, markj Tested by: mav, pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D11697 Notes: svn path=/head/; revision=321581
* Extract calculation of ioflags from the vm_pager_putpages flags into aKonstantin Belousov2017-04-051-1/+1
| | | | | | | | | | | | | helper. Reviewed by: markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week X-Differential revision: https://reviews.freebsd.org/D10241 Notes: svn path=/head/; revision=316526
* Use int instead of boolean_t for flags argument type inKonstantin Belousov2017-04-051-2/+1
| | | | | | | | | | | | | | vnode_pager_generic_putpages() prototype; change the argument name to reflect that it is flags. Reviewed by: markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week X-Differential revision: https://reviews.freebsd.org/D10241 Notes: svn path=/head/; revision=316524
* Renumber copyright clause 4Warner Losh2017-02-281-1/+1
| | | | | | | | | | | | Renumber cluase 4 to 3, per what everybody else did when BSD granted them permission to remove clause 3. My insistance on keeping the same numbering for legal reasons is too pedantic, so give up on that point. Submitted by: Jan Schaumann <jschauma@stevens.edu> Pull Request: https://github.com/freebsd/freebsd/pull/96 Notes: svn path=/head/; revision=314436
* A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES().Gleb Smirnoff2015-12-161-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | o With new KPI consumers can request contiguous ranges of pages, and unlike before, all pages will be kept busied on return, like it was done before with the 'reqpage' only. Now the reqpage goes away. With new interface it is easier to implement code protected from race conditions. Such arrayed requests for now should be preceeded by a call to vm_pager_haspage() to make sure that request is possible. This could be improved later, making vm_pager_haspage() obsolete. Strenghtening the promises on the business of the array of pages allows us to remove such hacks as swp_pager_free_nrpage() and vm_pager_free_nonreq(). o New KPI accepts two integer pointers that may optionally point at values for read ahead and read behind, that a pager may do, if it can. These pages are completely owned by pager, and not controlled by the caller. This shifts the UFS-specific readahead logic from vm_fault.c, which should be file system agnostic, into vnode_pager.c. It also removes one VOP_BMAP() request per hard fault. Discussed with: kib, alc, jeff, scottl Sponsored by: Nginx, Inc. Sponsored by: Netflix Notes: svn path=/head/; revision=292373
* Merge from projects/sendfile:Gleb Smirnoff2014-11-231-1/+2
| | | | | | | | | | | | | | | | | o Provide a new VOP_GETPAGES_ASYNC(), which works like VOP_GETPAGES(), but doesn't sleep. It returns immediately, and will execute the I/O done handler function that must be supplied as argument. o Provide VOP_GETPAGES_ASYNC() for the FFS, which uses vnode_pager. o Extend pagertab to support pgo_getpages_async method, and implement this method for vnode_pager. Reviewed by: kib Tested by: pho Sponsored by: Netflix Sponsored by: Nginx, Inc. Notes: svn path=/head/; revision=274914
* Remove redundant declaration. vnode.h should be included before vnode_pager.h.Gleb Smirnoff2014-09-151-1/+0
| | | | Notes: svn path=/head/; revision=271631
* Provide the unique implementation for the VOP_GETPAGES() method usedKonstantin Belousov2014-09-151-0/+2
| | | | | | | | | | | | by ffs and ext2fs. Remove duplicated call to vm_page_zero_invalid(), done by VOP and by vm_pager_getpages(). Use vm_pager_free_nonreq(). Reviewed by: alc (previous version) Sponsored by: The FreeBSD Foundation MFC after: 6 weeks (after r271596) Notes: svn path=/head/; revision=271619
* Account the writeable shared mappings backed by file in the vnodeKonstantin Belousov2012-02-231-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | v_writecount. Keep the amount of the virtual address space used by the mappings in the new vm_object un_pager.vnp.writemappings counter. The vnode v_writecount is incremented when writemappings gets non-zero value, and decremented when writemappings is returned to zero. Writeable shared vnode-backed mappings are accounted for in vm_mmap(), and vm_map_insert() is instructed to set MAP_ENTRY_VN_WRITECNT flag on the created map entry. During deferred map entry deallocation, vm_map_process_deferred() checks for MAP_ENTRY_VN_WRITECOUNT and decrements writemappings for the vm object. Now, the writeable mount cannot be demoted to read-only while writeable shared mappings of the vnodes from the mount point exist. Also, execve(2) fails for such files with ETXTBUSY, as it should be. Noted by: tegge Reviewed by: tegge (long time ago, early version), alc Tested by: pho MFC after: 3 weeks Notes: svn path=/head/; revision=232071
* Remove wrong comment.Konstantin Belousov2012-02-221-4/+0
| | | | | | | | Discussed with: alc MFC after: 3 days Notes: svn path=/head/; revision=232002
* In the VOP_PUTPAGES() implementations, change the default error fromKonstantin Belousov2011-06-011-0/+3
| | | | | | | | | | | | | | | | | | | VM_PAGER_AGAIN to VM_PAGER_ERROR for the uwritten pages. Return VM_PAGER_AGAIN for the partially written page. Always forward at least one page in the loop of vm_object_page_clean(). VM_PAGER_ERROR causes the page reactivation and does not clear the page dirty state, so the write is not lost. The change fixes an infinite loop in vm_object_page_clean() when the filesystem returns permanent errors for some page writes. Reported and tested by: gavin Reviewed by: alc, rmacklem MFC after: 1 week Notes: svn path=/head/; revision=222586
* Do not sleep for vnode lock while holding map lock in vm_fault. Try toKonstantin Belousov2009-02-081-1/+0
| | | | | | | | | | | | | | | | | | acquire vnode lock for OBJT_VNODE object after map lock is dropped. Because we have the busy page(s) in the object, sleeping there would result in deadlock with vnode resize. Try to get lock without sleeping, and, if the attempt failed, drop the state, lock the vnode, and restart the fault handler from the start with already locked vnode. Because the vnode_pager_lock() function is inlined in vm_fault(), axe it. Based on suggestion by: alc Reviewed by: tegge, alc Tested by: pho Notes: svn path=/head/; revision=188331
* Move the body of vop_stdcreatevobject() over to the vnode_pager underPoul-Henning Kamp2005-01-241-1/+0
| | | | | | | | | | | | | | the name Sande^H^H^H^H^Hvnode_create_vobject(). Make the new function take a size argument which removes the need for a VOP_STAT() or a very pessimistic guess for disks. Call that new function from vop_stdcreatevobject(). Make vnode_pager_alloc() private now that its only user came home. Notes: svn path=/head/; revision=140767
* /* -> /*- for license, minor formatting changesWarner Losh2005-01-071-1/+1
| | | | Notes: svn path=/head/; revision=139825
* Remove advertising clause from University of California Regent's license,Warner Losh2004-04-061-4/+0
| | | | | | | | | per letter dated July 22, 1999. Approved by: core Notes: svn path=/head/; revision=127961
* Remove __P.Alfred Perlstein2002-03-191-6/+6
| | | | Notes: svn path=/head/; revision=92727
* - Remove a number of extra newlines that do not belong here according toEivind Eklund2002-03-101-2/+1
| | | | | | | | | | | | style(9) - Minor space adjustment in cases where we have "( ", " )", if(), return(), while(), for(), etc. - Add /* SYMBOL */ after a few #endifs. Reviewed by: alc Notes: svn path=/head/; revision=92029
* vnode_pager_freepage() is really vm_page_free() in disguise,Alfred Perlstein2001-04-191-1/+0
| | | | | | | nuke vnode_pager_freepage() and replace all calls to it with vm_page_free() Notes: svn path=/head/; revision=75692
* Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"Peter Wemm1999-12-291-1/+1
| | | | | | | | | is an application space macro and the applications are supposed to be free to use it as they please (but cannot). This is consistant with the other BSD's who made this change quite some time ago. More commits to come. Notes: svn path=/head/; revision=55206
* $Id$ -> $FreeBSD$Peter Wemm1999-08-281-1/+1
| | | | Notes: svn path=/head/; revision=50477
* Fixed two potentially serious classes of bugs:David Greenman1998-10-131-2/+2
| | | | | | | | | | | | | | | | | | | 1) The vnode pager wasn't properly tracking the file size due to "size" being page rounded in some cases and not in others. This sometimes resulted in corrupted files. First noticed by Terry Lambert. Fixed by changing the "size" pager_alloc parameter to be a 64bit byte value (as opposed to a 32bit page index) and changing the pagers and their callers to deal with this properly. 2) Fixed a bogus type cast in round_page() and trunc_page() that caused some 64bit offsets and sizes to be scrambled. Removing the cast required adding casts at a few dozen callers. There may be problems with other bogus casts in close-by macros. A quick check seemed to indicate that those were okay, however. Notes: svn path=/head/; revision=40286
* In the author's words:Mike Smith1998-02-261-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | These diffs implement the first stage of a VOP_{GET|PUT}PAGES pushdown for local media FS's. See ffs_putpages in /sys/ufs/ufs/ufs_readwrite.c for implementation details for generic *_{get|put}pages for local media FS's. Support is trivial to add for any FS that formerly relied on the default behaviour of the vnode_pager in in EOPNOTSUPP cases (just copy the ffs_getpages() code for the FS in question's *_{get|put}pages). Obviously, it would be better if each local media FS implemented a more optimal method, instead of calling an exported interface from the /sys/vm/vnode_pager.c, but this is a necessary first step in getting the FS's to a point where they can be supplied with better implementations on a case-by-case basis. Obviously, the cd9660_putpages() can be rather trivial (since it is a read-only FS type 8-)). A slight (temporary) modification is made to print a diagnostic message in the case where the underlying filesystem attempts to engage in the previous behaviour. Failure is likely to be ungraceful. Submitted by: terry@freebsd.org (Terry Lambert) Notes: svn path=/head/; revision=33847
* Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are notPeter Wemm1997-02-221-1/+1
| | | | | | | ready for it yet. Notes: svn path=/head/; revision=22975
* Make the long-awaited change from $Id$ to $FreeBSD$Jordan K. Hubbard1997-01-141-1/+1
| | | | | | | | | | | This will make a number of things easier in the future, as well as (finally!) avoiding the Id-smashing problem which has plagued developers for so long. Boy, I'm glad we're not using sup anymore. This update would have been insane otherwise. Notes: svn path=/head/; revision=21673
* Another mega commit to staticize things.Poul-Henning Kamp1995-12-141-6/+2
| | | | Notes: svn path=/head/; revision=12820
* Changes to support 1Tb filesizes. Pages are now named by anJohn Dyson1995-12-111-3/+3
| | | | | | | (object,index) pair instead of (object,offset) pair. Notes: svn path=/head/; revision=12767
* Minor performance improvements, additional prototype for additionalJohn Dyson1995-09-061-1/+2
| | | | | | | exported symbol. Notes: svn path=/head/; revision=10576
* NOTE: libkvm, w, ps, 'top', and any other utility which depends on structDavid Greenman1995-07-131-12/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers). Notes: svn path=/head/; revision=9507
* These changes embody the support of the fully coherent merged VM buffer cache,David Greenman1995-01-091-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman Notes: svn path=/head/; revision=5455
* Added $Id$David Greenman1994-08-021-0/+1
| | | | Notes: svn path=/head/; revision=1817
* The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch.Rodney W. Grimes1994-05-251-3/+0
| | | | | | | | Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman Notes: svn path=/head/; revision=1549
* BSD 4.4 Lite Kernel SourcesRodney W. Grimes1994-05-241-0/+59
Notes: svn path=/head/; revision=1541
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